Sealed switch unit



Jan. 7, 1969 H. w. RIKE SEALED SWITCH UNIT Filed A ril 26, 1967 I .Illllll INVENTOR flag wo W AIKE United States Patent 9 Claims ABSTRACT OF THE DISCLOSURE A submersible motor-pump has a start winding connected in circuit through a centrifugally actuated hermetically sealed switch. A centrifugally actuated and pivotally mounted actuator is secured to the shaft and actuates a switch lever. The actuator is enclosed within a cover member having an opening aligned with the end of the lever. The switch includes a pair of leaf spring contact arms in the housing and integral contacts extend through sealed housing openings. The lever is L-shaped and one arm is mounted in one end of the housing to move the contact arms and the second arm terminates in a flanged button aligned with the cover opening. The first arm of the lever is centrally secured to a flexible gasket and diaphragm which is clamped between a pair of plate members, the outer one of which seals the adjacent end of the housing. The clamping plates are provided with openings somewhat larger than the L-shaped switch arm and with recesses surrounding the opening in the faces abutting the diaphragm. The diaphragm serves to seal the opening as the hinge permits pivotal movement of the arm in response to retraction of the actuator from the flanged button. The flanged button then serves to essentially close the opening.

This invention relates to a hermetically sealed electrical switch and particularly to a switch employed in connection with electric motors and the like.

In many single phase motors and the like, a centrifugal- 'ly actuated switch is employed to cut out a starting winding. However they have certain distinct advantages from the standpont of satisfactory life due to the environmental conditions. For example, in a submersible motor, the mounting of a switch within the liquid in the motor chamber may substantially reduce the life and general satisfactory operating characteristics of the switch.

Although hermetically sealed switches have been suggested, none have been found to provide the desired reliable long life operation required in submersible motors. Thus, submersible motors are normally disposed Within a Well and should operate continuously and satisfactorily in excess of 10 years or more because of the expense and inconvenience attendant the replacement and disruption of operation.

The present invention is particularly directed to a simple and reliable means of providing a hermetically sealed switch having an external switch operating arm. Generally, in accordance with the present invention, the switch contacts are disposed within a housing and the operating arm extends through an opening in the housing. In accordance with the present invention, the member extends through a gasket or diaphragm formed of a rubber or similar synthetic pliable material and is hermetically sealed thereto. For example, a highly satisfactory assembly employed rubber vulcanized to the actuating member. The diaphragm is generally a plate-like member clamped between an inner clamping member and an outer clamping member having an opening substantially larger than the size of the operating arm. The outer clamping member is interconnected to the housing and the diaphragm serves to seal the corresponding housing opening with the inner 3,420,974 Patented Jan. 7, 1969 end of the arm disposed adjacent the contacts for actuating the same in response to a pivoting force applied to the outer end of the operating arm. In accordance with the present invention, the clamping members are plates recessed immediately adjacent and about the plate openings such that the adjacent portion of the diaphragm is relieved. It has been found that this provides a highly reliable and improved switch operator which has a very long life. The recessed faces have been found to produce excellent unrestrained hinge action.

In a liquid-filled submersible motor or the like, the switch is mounted adjacent the bottom free end of the shaft. A centrifugal actuator is pivotally mounted to the free end of the shaft and pivots about an axis normal to the shaft to position the switch operating arm. A cover is secured about the actuator with a single opening aligned with the end of the switch operating arm. A flanged button or the like is secured to the arm and extends through the opening in the cover. When the actuator pivots to release the switch, the arm pivots and the flange rests upon the cover. This substantially reduces turbulence of the liquid normally caused by the rotation of the actuator and substantially minimizes losses associated with such turbulence. For example, tests conducted on a motor showed the losses were reduced by 40 watts.

The drawing furnished herewith illustrates a preferred construction of the present invention in which the above advantages and features are clearly disclosed as Well as others which will be clear from the following description.

In the drawings:

FIG. 1 is a side elevational view of a submersible motorpump unit with parts broken away to show the switch and operating mounting in one embodiment of the present invention;

FIG. 2 is an end view of the switch structure shown in FIG. 1;

FIG. 3 is a longitudinal section taken on line 33 of FIG. 2; and

FIG. 4 is an enlarged elevational view with parts broken away showing the switch structure.

Referring to the drawings and particularly to FIG. 1, a submersible motor-pump unit 1 is shown having a submersible motor 2 interconnected to drive a pump 3 and having a liquid inlet 4 therebetween. The unit is adapted to be disposed within a well casing or the like with the motor 2 disposed below the pump 3 and immersed within the Well liquid. The motor 2 is energized whenever water is to be withdrawn from the well. The illustrated motor 2 is generally an oil-filled unit and the lower end of which is sealed and provided with an expansion bag 5 adapted to maintain the oil within the motor 2 under pressure such that any leakage past the upper shaft bearing, not shown, is outwardly of the motor.

As is well known, such motors may be of the capacitor start variety wherein a starting winding, not separately shown, is interconnected in circuit during the starting of the motor. A phase or control switch unit 6 is secured Within and immediately adjacent the lower end of the motor shaft 7 and includes a contact arm or lever 8 aligned with an end mounted centrifugal actuator 9 for actuation of the switch unit 6.

Generally, the actuator 9 includes a weighted arm 10 pivotally secured to the lower end of the motor shaft 7 by a pivot bracket 11. The arm 10 is shown in the standby position with the one end of the arm projecting downwardly into engagement with the contact lever 8 of the phase switch unit 6. Rotation of the rotor and the attached motor shaft 7 establishes centrifugal forces on the arm 10 tending to pivot it in a counterclockwise direction as viewed in FIG. 1. At a selected speed, the centrifugal force will be such as to cause a snap action movement of the arm 10 from the full line position to the dotted line position shown thereby relieving the phase switch lever 8 which pivots as hereinafter described to open the switch unit 6 and remove the start winding circuit.

Referring particularly to FIGS. 2-4, a phase switch unit 6 constructed in accordance with the present invention is shown including a housing 12 having a generally rectangular section. The one end of the housing is open and the opposite or lower end of the housing 12 is closed with an integral bottom wall 13 having a pair of spaced contact openings within which suit-able contact means are mounted in sealed relation.

In the illustrated embodiment, similar leaf spring contacts 14 and 15 are mounted one each within the openings. Each of the leaf spring contacts 14 and 15 is similarly constructed and consequently the one contact 14 will be described in some detail with the corresponding elements of the other contacts similarly identified by primed numbers.

Generally, the contact 14 includes a leaf spring having a contact button 16 welded or soldered to the inner end thereof. A mounting stud 17 is provided having a notched head within which the leaf spring is wedged and soldered or otherwise connected to provide a good electrical interconnection therebetween. A stop plate 18 also extends into the slot of the stud head and extends the partial length of the arm terminating in slight relation to the contact button 16. Contact 15 is not provided with a similar plate. The stud 17 projects outwardly through the appropriate opening in the base or bottom wall 13 of the housing 12. A clamping washer and nut assembly 19 is threaded onto the stud to securely clamp the contact to the housing. A sealing gasket 20 is disposed between the assembly 19 and the housing 12 to provide a hermetic seal about the stud 17. A winding lead 21 is connected to the stud 17 through a suitable connecting nut 22.

As most clearly shown in FIG. 2, the openings for the studs 17 and 17 are formed in the housing at a slight angle with the axis of the housing to locate the contact buttons 16 and 16' in overlapping opposed relation.

The open end of the housing is sealed by a closure assembly including the contact arm or lever 8. In the illustrated embodiment of the invention, the lever 8 is an L-shaped member having a first leg or arm extending through a flexible member 23 serving as a sealing gasket and a pivot support diaphragm.

In the illustrated embodiment of the invention, the member 23 is shown as a flat sheet of rubber vulcanized to the adjacent arm of lever 8 and having a vulcanized hub 24 adjacent the lever. The member 23 is as large as the open end of the housing 12 and is clamped to the end face of the housing 12 by a pair of clamping members including an inner clamping plate 25 and an outer clamping and sealing plate 26.

The inner plate 25 is a generally rectangular plate resting in a corresponding recess 27 on the inner end edge of the housing 12 and with an outer or exterior face coplanar with the end of the housing 12. Plate 25 includes a rectangular opening 28 somewhat larger than the cross sec-tion of the contact arm of lever 8 with the one lever arm projecting centrally therethrough. The outer or exterior face of the plate 25 abutting the member 23 is further provided with a slight recess 29 surrounding the opening 28 to relieve the gasket 23 immediately adjacent such opening.

The outer plate 26 is somewhat larger than the cross section of housing 12 and includes integral attachment or mounting lips 30 to opposite sides of the housing 12.

Plate 26 and gasket 23 include similar bolt openings through which clamping bolts 31 project and thread into suitably tapped openings in the end face of the housing 12.

The clamping plate 26 is also provided with an opening 32 larger than the cross section of the outer arm of lever 8 and further larger than the hub 24 of gasket 23. Up-

standing shoulders or projections 33 on the plate 26 are also provided with the outer arm of the switch lever 8 guided therebetween. The inner face of the plate 26 abutting the member 23 includes a recess 34 about the opening 32 to provide further relief of the gasket 23 immediately adjacent the hinge connection.

The lever 8 has a generally rectangular cross section and the inner end of the arm extending into the housing 12 is provided with a contact button 35 secured thereto in any suitable manner. The button 35 is aligned with the free ends of the contacts 14 and 15.

The outer arm of the lever 8 extends generally laterally of the switch housing 12 and a flanged bearing button 36 of plastic or the like is aligned with the arm 10' of switch actuator 9.

The illustrated embodiment of the invention includes a protective cover 37 secured to the bearing hub 38 for shaft 7 and substantially enclosing the actuator 9. The illustrated cover 37 is a cup-shaped member having its upper edge fitted and sealed within a recess in a depending flange 39 and the hub 38. A central opening 40 in the bottom wall of the cover is aligned with the flanged button 36. The button 36 includes a flange 41 which has a diameter slightly larger than the opening. The spring force on the arm or lever 8 continuously urges the button 36 into opening 40 and the flange 41 into firm engagement with the cover. In the motor standby or stop condition, the operating end portion of actuator 10 en gages button 36 and spaces the flange 41 from the opening 40. However, when the motor is running, the button 36 is released and the flange 41 moves into engagement with the cover to essentially close the opening 40. This substantially reduces turbulence of the liquid normally caused by the rotation of the actuator and substantially minimizes losses associated with such turbulence. For example, tests conducted on a motor showed the losses were reduced by 40 watts.

The switch unit '6 is secured in place within the motor 2, as shown in FIG. 1. In particular, a pair of U-shaped brackets 42 are bolted to suitably threaded openings in the mounting lips 30 of outer plate 26. The opposite arms of brackets 42 are spot welded or otherwise secured to the bottom wall of the cover 37 to properly dispose the flanged button 36 in alignment with the central cover opening 40.

In the initial assembly, the switch unit 6 is in the position shown in FIG. 1 with the leaf spring contacts 14 and 15 closed. When the switch unit 6 is assembled within the motor and with the actuator 9 in the normal position, the arm 10 of the actuator 9 holds the lever 8 pivoted at the connection to the flexible rubber-like member which provides a reliable hinge support. When the motor 2 is energized, selected speed of the rotor rotation causes the arm 10 of the actuator 9 to move to the actuated position where it is held until the motor reduces speed. This relieves the force on the switch lever 8 and member 23 which causes lever 8 to pivot to the position shown in FIG. 4 and then places switch unit 6 in the normally open position with the flange 41 engaging cover 37 to essentially form a closed chamber about the actuator 9.

In this manner, a start winding, not shown, is disconnected from the circuit during normal running operation.

The use of the sealing gasket and diaphragm of a rubber-like material hermetically secured to the lever 8 as by a vulcanized rubber connection has been found to provide a highly reliable means for hermetically sealing of the switch unit 6 and providing a reliable hinge having a long life. Applicant has found employing a rubber-like material for member 23 is particularly useful in connection with submersible motors. Applicant has particularly found that the provision of the recesses 29 and 34 adjacent the hinged connection provides a highly improved result. It would appear that the larger volume of free or unrestricted rubber provides optimum hinge action.

Additionally, the enclosure of the actuator 9 under running conditions minimizes power losses as a result of reduced turbulence and circulation.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. In a liquid filled motor having a switch unit actuated by a centrifugal actuator secured to a motor shaft, said actuator including an operating member pivotally mounted as a part of the actuator for pivotal movement about a given axis in response to rotation of the shaft and actuator about the axis of the shaft, the improvement comprising stationary means enclosing said shaft and said actuator including said operating member to essentially eliminate turbulence of the liquid as a result of the rotation of the actuator during operation of the motor.

2. In a liquid filled motor having a switch unit actuated by a centrifugal actuator secured to the shaft, said actuator having an operating portion pivotal about an axis normal to the shaft, the improvement comprising a cover secured about said actuator and having an opening aligned with the operating portion of the actuator, said switch unit having an operating member with a flanged portion, and means to mount said switch unit with,the flanged portion aligned with said opening and said operating portion and biased to engage the cover to essentially close said opening with the operating portion engaging the flanged portion and holding the flanged portion in spaced relation to the cover in the stop position of the motor and releasing the flanged portion with the flanged portion resting on the cover when the motor is running.

3. In the submersible motor of claim 2 wherein said actuator is secured to a free end of the shaft and the cover encloses the actuator and free end of the shaft, said cover having an opening in the bottom wall aligned with said operating portion of the actuator.

4. In the submersible motor of claim 2 wherein said switch unit includes a housing with switch contacts therein and a housing opening through which a contact lever is mounted, a flexible sealing member formed of a resilient rubber-like material, said member having an opening with the lever extending therethrough, said member being hermetically attached to the lever, clamping members disposed to opposite sides of the flexible sealing member and having openings larger than the lever and smaller than the housing opening, and means to interconnect the clamping members and the flexible sealing member to the housing to seal the housing opening and to hingedly mount the lever for actuation of said contacts.

5. In the submersible motor of claim 4 wherein said sealing member is a flat sheet and said clamping members are plates disposed to opposite sides of the sheet, said plates having said openings and having recesses surrounding the openings in the face abutting said flat sheet.

6. In a sealed switch unit having a housing with switch contacts therein and a housing opening through which a contact lever is mounted, the improvement comprising a flexible sealing member formed of a resilient rubber-like material, said member having an opening with the lever extending therethrough, said member being hermetically attached to the lever, clamping members disposed to opposite sides of the flexible sealing member and having openings larger than the lever and smaller than the housing opening, said housing having a recess on the inner edge of the housing opening, a first of said clamping members disposed within said recess, said sealing member and other clamping member overlying the opening and adjacent portion of the housing, and means securing said other clamping member to the housing to compress said flexible sealing means and hermetically seal the opening.

7. In the sealed switch unit of claim 6 wherein the flexible sealing member is vulcanized to the lever.

8. The sealed switch unit of claim 6 wherein the housing is a tubular member open at one end and closed at the other with the contacts mounted in the closed end, the open end of the housing being provided with a plurality of tapped axial openings, the flexible sealing member being a flat sheet of rubber and being vulcanized to the lever, the one clamping member being a plate disposed to the inner side of the flexible sealing member and mating with said recess with the outer face being coplanar with the outer end, the other clamping member being a plate and overlying the open end of the housing, bolts passing through said other clamping member and the flexible sealing member and threaded into the tapped openings in the housing, and said plates being recessed in the face abutting the sealing member about the openings to establish selected unrestrained movement of the sealing member.

9. In a sealed switch unit having a housing with switch contacts therein and a housing opening through which a contact lever is mounted, the improvement comprising a flexible sealing member formed of a flat sheet of resilient rubber-like material, said member having an opening with the lever extending therethrough, said member being hermetically attached to the lever, flat clamping plates disposed to opposite sides of the flat sheet and having openings larger than the lever and smaller than the housing opening, said plates having recesses surrounding the openings in the face of each plate abutting the flat sheet, and means to interconnect the outer peripheral portions of the clamping plates and the flat sheet to the housing in spaced relation to the openings and the recesses and thereby sealing the housing opening and hingedly mounting the lever for actuation of said contacts.

References Cited UNITED STATES PATENTS 2,726,105 12/1955 Koenig 200l68 2,744,984 5/1956 Hults 200-168 3,237,460 3/1966 Morse 200168 3,250,927 5/1966 Lung ZOO- ROBERT K. SCHAEFER, Primary Examiner. H. O. JONES, Assistant Examiner.

US. Cl. X.R. ZOO-80 

